Method of making brake linings



Patented July 23, 1929.

UNITED STATES PATENT OFFICE.

SAMUEL HUGHES, OF NORTH CHARLESTON, SOUTH CAROLINA, ASSIGNOR TO THE BAY-IBESTOS COMPANY, OF BRIDGEPORT, CONNECTICUT, A CORPORATION OF CONNECT-ICUT.

No Drawing.

This invention relates to the making of friction elements, particularlybrake lining for motor vehicles, and hasfor an object to provide amethod of making improved brake lining which will reduce to a mmimum thesqueal of the-brakes.

It is also an object of the invention to reduce the tendency of thebrake lining to grab, and thus gives a smoother and more uniformlyacting lining.

It is a further object of the invention to produce a brake lining havinga less tendency to bleed than the linings now commonly in use, and toalso reduce the tendency to score the drums.

It is a further object of the invention to reduce the tendency tobinding and abrasion of the yarn in the process of weaving, and thusreduce to a minimum the present difliculties which give trouble inweaving.

With the foregoing and other objects in view, my invention consists in anovel method of making brake linings and similar friction articles whichwill be more fully disclosed as the description proceeds. The inventionconsists broadly in moistening the yarn used for Weaving the brakelining or friction element with a suitable liquid, such as gasoline,kerosene, water and so forth. Very satisfactory results have beensecured by using water. Such a liquid as is used is not intended as apermanent saturant for the brake lining but is intended only as acarrier for the carbon and is later evaporated. After the yarn isthoroughly moistened the surface is covered with a coating of powderedcarbon, such as graphite or charcoal. This coated yarn is then woveninto the brake lining, and the woven lining is then saturated with asuitable liquid binder and cured by any of the known methods, as by theapplication of heat or of heat and pressure. In the event the liquidused is water it ordinarily is dried out or evaporated before the liningis treated with the permanent saturant. If kerosene or gasoline andsimilar liquids are used they may be evaporated either before or in thecuring process.

In a specific operation which has been employed a tube or a spool offilling yarn, such for example as asbestos yarn or yarn composed ofasbestos and sufiicient cotton to give the re uired strength, wasimmersed in some auitab e liquid, such as gasoline, kerosene orApplication filed November 14, 1928.

Serial No. 319,451.

water and so forth. After the spools of yarn were thoroughly saturatedthey were taken to the cop winder for winding the filling for the loomshuttles. The wet spools of yarn were placed on the cop winder stand andthe yarn led down into a vessel containing dry powdered carbon, such asgraphite or charcoal, passed under a bar or other suit- .able guide atthe bottom of this vessel, and

then up and out into the winder head where it was wound into cops forthe filling. On its passage through the dry powdered carbon the wet yarnpicked up a continuous coatingof this carbon. The coated fillin yarn wasthen placed in loom shuttles and woven into brake lining in the usualmanner. The lining was then saturated with a suitable liquid binder andcured by the application of heat or heat and pressure.

The lining produced by this method has practically no tendency tosqueal, and it will be apparent that the method is a very simple one andis not an expensive process to use. The application of the carbon to theyarn before it is woven introduces the carbon into the very body of thelining, and therefore, the treatment is not a mere surface treatment ofthe lining which soon wears off, but is auniform treatment throughoutthe entire body of the lining. This treatment also reduces the tendencyof the lining to grab the drum, thus giving a much smoother action, andit reduces the tendency to score the drum. The carbon, especially thecharcoal, absorbs the excessive saturant used in the curing of thelining and thus reduces the tendency of the lining to bleed. It,therefore, prevents gumming up of the drum.

Another important advantage of this method is that the carbon on thesurface of the yarn reduces or practically eliminates the drag on theyarn in the weaving, particularly as the yarn passes through the guideson the shuttles. In other words it reduces the tendency to binding orabrasion of the yarn in the process of weaving. In weaving, even aslight tendency to drag causes trouble, particularly in the case ofasbestos yarn which does not have great tensile strength, and it will beseen that this surface coating of carbon facilitates the freer passageof the yarn through the guides, thus re ucmg the tendency of the jam todrag.-

' invention, what I claim is:

weaving the 1. A method of making a brake lining which comprisesmoistening a yarn, passing the wet yarn through powdered carbon wherebyit picks up a coating of this carbon, am into a lining, saturating thelining Wit a suitable binder, and curing with the application of heat. a

2. A method of making a brake lining comprising moistening a yarn,applying powdered carbon to the surface of the moistened yarn, weavingthe yarn into a lining,

saturating the lining with a liquid binder, and curing.

3. A method of reducing the tendenc of a woven yarn brake lining tosqueal, b eed, and grab and score the drum, which comprises applying tothe yarn before it is woven a coating of powdered carbon, weaving thecoated yarn into a lining, saturating the Woven lining with a liquidbinder, and curing.

In testimony whereof I affix my signature.

SAMUEL HUGHES.

